Individuals regenerated from the head, middle and tail-sections of Dugesia dorotocephala (Woodworth) were studied in the laboratory to ascertain their predatory and asexual reproductive potential. In two predatory experiments head-sectioned Dugesia consumed a larger number of Culex p. quinquifasciatus larvae during the first 24 hours than either the middle or tail-sectioned Dugesia. At low predator-prey ratio, the maximum consumption was low while at higher ratio of 20 to 50/replicate predation percentages were higher. A total of 98, 97 and 95.5% larvae were consumed by the unsectioned, head and middle-sectioned groups respectively. Asexual reproduction was highest among tail-sectioned Dugesia in two tests, increasing from an initial 100 to 280 in 30 days, while the unsectioned control increased to only 262. In all tests Dugesia doubled their initial numbers in 20 days. Part 1 of 10.